The Muscle-Joint Connection: The Effects of Muscle Loss on Mobility

From the moment of birth (or even before), babies build muscle. As they grow more active, learn to turn over, crawl, stand, and take those first exciting baby steps, youngsters are strengthening and increasing the size of their muscles.
Muscle Mass Peak and Decline
This process continues until around age 30 (or as old as the 40s for women), when age-related muscle loss, aka sarcopenia, sets in. The reduction in both the amount of muscle mass and the number and size of fibers is so gradual that individuals may be unaware of the change. As people approach their golden years, quickly-contracting muscle fibers decrease in number at a much faster rate than slowly-contracting ones. Baby boomers tend to notice increased weakness and less ability to move quickly than their younger counterparts. However, elderly athletes discover heightened a capability in activities involving endurance even as their capacity for speed diminishes.
Yet, growing older is not the only cause of loss of muscle mass. The following types of atrophy (muscle wasting) can occur at any age.
• Disuse atrophy. Couch potato syndrome is one form of this kind of muscle loss. Physical disorders that make movement difficult, sedentary work, and even a few days in a weightless environment can also adversely affect muscle strength.
• Neurogenic atrophy. Diseases affecting nerves that send commands from the brain to muscles fall into this category. Multiple sclerosis, Guillain-Barre Syndrome, an autoimmune disease characterized by nerve inflammation and feeble muscles, and neuropathy, when damaged nerves have a negative effect on muscular capabilities, are a few examples.
• Illness- or trauma-related atrophy. Causes of this category of diminished muscle mass are varied: malnutrition, burns, fractures and other injuries, heavy drinking over a lengthy period of time, osteoarthritis, and the use of corticosteroids and other medications.
The Muscle-Joint Connection
Whether the loss of muscle tissue and strength is a natural part of aging or due to illness, injury, or lifestyle, the effect on joints is inevitable. Weakened muscles put a strain on those places where bone connects to bone; the knees are particularly vulnerable. Joint issues range from minor stiffness to more problematic conditions like the above-mentioned osteoarthritis (in which the cartilage cushion protecting joints wears down, resulting in swelling, discomfort, and motion difficulty). Even more potentially serious consequences of diminished muscle mass are loss of balance, differences in gait, difficulties in standing or walking, and the possibility of falls—all of which can lead to injury and further atrophy or the necessity of surgery. In addition, muscle changes can lead to reduced reflexes.
Rest assured that diminished muscle strength and size—whatever the cause—does not mean an end to an active, pain-free life. Proper nutrition and exercise, while they might not turn a person into a real-life Popeye, can ensure enjoyment of physical activities well into one’s golden years.